September 2022 - vsnet-campaign-dn - ooruri.kusastro.kyoto-u.ac.jp

[vsnet-campaign-dn 16511] CY Ori: bright dwarf nova in Orion
by Taichi Kato 23 Sep '22

23 Sep '22

CY Ori: bright dwarf nova in Orion ASAS-SN data: https://asas-sn.osu.edu/sky-patrol/coordinate/50a88cf6-44c8-49b1-a409-8dacb… One of the brightest dwarf novae in Orion. Z Cam-type variable. The 2019 Oct-2020 Jan. standstill slowly brightened with some oscillations. Could be a signature of an IW And star, although typical IW And-type behavior has not yet been recorded. Long, bright outburst in 2021 Aug.-Sep. followed by smaller outbursts. The behavior is somewhat atypical and would require more observations. TESS data show very clear double-wave modulations (ellipsoidal with O'Connell effect) with Porb=0.279969(4) d. 061448.742 +093427.67 (2000.0) Gaia_DR2_3329059422060781184 plx=2.338(0.057) dismod=8.2 pmra=2.610(0.091) pmdec=-7.893(0.076) G=12.504 BP=12.744 RP=12.082 061448.742 +093427.67 (2000.0) Gaia_EDR3_3329059422060781184 plx=2.298(0.059) dismod=8.2 pmra=1.727(0.060) pmdec=-8.005(0.049) G=12.418 BP=12.632 RP=12.008

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[vsnet-campaign-dn 16510] ASASSN-19zy rare outburst
by Taichi Kato 21 Sep '22

21 Sep '22

ASASSN-19zy rare outburst Past superoutburst in 2019. Superhumps were not well covered by observations. YYYYMMDD(UT) mag observer 20220913.6200 <154c (Yutaka Maeda) 20220915.6800 <167c (Yutaka Maeda) 20220919.6499 146c (Yutaka Maeda)

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[vsnet-campaign-dn 16509] ASASSN-22lj
by Taichi Kato 21 Sep '22

21 Sep '22

ASASSN-22lj Also a bright, large-amplitude dwarf nova. ASASSN-22lj -- ------- 8:24:18.55 -24:57:37.3 2022-09-18.37 12.82 SDSS DSS VIZIER ------- CV candidate, matches to PS1 g=19.5, g>17.2 on 2022-09-08.13, g=12.3 on 2022-09-14.15, g=12.5 on 2022-09-15.15, g=13.2 on 2022-09-18.37 082418.608 -245737.68 (2000.0) Gaia_DR2_5696080563913025024 plx=2.306(0.309) dismod=8.2 pmra=7.197(0.469) pmdec=-13.579(0.441) G=19.397 BP=19.320 RP=19.121 082418.608 -245737.68 (2000.0) Gaia_EDR3_5696080563913025024 plx=2.565(0.229) dismod=8.0 pmra=7.131(0.190) pmdec=-13.754(0.193) G=19.345 BP=19.443 RP=19.193

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[vsnet-campaign-dn 16508] ASASSN-22lk: bright transient
by Taichi Kato 20 Sep '22

20 Sep '22

ASASSN-22lk: bright transient ASASSN-22lk -- ------- 18:54:33.41 11:56:6.1 2022-09-18.19 11.63 SDSS DSS VIZIER ------- CV candidate, matches to PS1 g=20.5, g>17.7 on 2022-09-17.22, g=12.1 on 2022-09-18.18 185433.474 +115606.25 (2000.0) Gaia_DR2_4504346470647563008 plx=5.407(0.857) dismod=6.3 pmra=-2.475(1.526) pmdec=-18.109(2.153) G=20.298 BP=20.304 RP=19.989 185433.474 +115606.25 (2000.0) Gaia_EDR3_4504346470647563008 plx=3.328(0.642) dismod=7.4 pmra=-1.831(0.593) pmdec=-13.594(0.604) G=20.258 BP=20.417 RP=20.390

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[vsnet-campaign-dn 16506] ZTF22abfjnpj: new SU UMa-type dwarf nova
by Yusuke Tampo 16 Sep '22

16 Sep '22

ZTF22abfjnpj: new SU UMa-type dwarf nova Kyoto Univ. team and Moriyama-san reported the observations of ZTF22abfjnpj = AT 2022tru. This object was discovered by ZTF on 7th Sep. with the outburst amplitude of 8 mag, and spectroscopically classified as a CV by Dr. Claudio Balcon. https://www.wis-tns.org/object/2022tru Our observation at Kyoto Univ. on 15th Sep. detected a 0.2-mag superhump with a period of ~0.056 d. Therefore, ZTF22abfjnpj is likely a SU UMa-type dwarf nova, and also can be a WZ Sge-type dwarf nova based on its large outburst amplitude and short superhump period. Time-resolved observations are encouraged to determine its superhump periods. Best, Yusuke -- ---------------------------------------------- 京都大学大学院理学研究科宇宙物理学教室 D2 Kyoto University, Graduate School of Department of Astronomy, PhD student 反保雄介 Yusuke TAMPO MAIL: tampo(a)kusastro.kyoto-u.ac.jp ----------------------------------------------

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[vsnet-campaign-dn 16505] ASASSN-22lf
by Taichi Kato 16 Sep '22

16 Sep '22

ASASSN-22lf ASASSN-22lf --- ------- 20:37:31.05 14:23:39.2 2022-09-14.38 15.34 SDSS DSS VIZIER ------- CV candidate, no Vizier match, g>17.1 on 2022-09-11.05, g=16.9 on 2022-09-12.80, g=15.7 on 2022-09-14.37, g=14.2 on 2022-09-15.13 Precursor and main outburst? Reaching mag 13. The initial outburst was too short for an ordinary dwarf nova, but might be possible for an ultrashort period binary. Amplitude too large for IP outbursts. https://asas-sn.osu.edu/sky-patrol/coordinate/8ac611f2-d397-4749-985e-5a9a9…

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[vsnet-campaign-dn 16504] Re: MASTER OT J001204.00-412337.4: fourth rebeightening
by Taichi Kato 15 Sep '22

15 Sep '22

Re: MASTER OT J001204.00-412337.4: fourth rebeightening According to observations by Josch Hambsch, the object is becoming brighter between rebeightenings. It may enter a standstill-like phase as frequently seen in AM CVn-type outbursts, but not common in hydrogen-rich system.

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[vsnet-campaign-dn 16503] MASTER OT J001204.00-412337.4: fourth rebeightening
by Taichi Kato 14 Sep '22

14 Sep '22

MASTER OT J001204.00-412337.4: fourth rebeightening Josch Hambsch detected the fourth rebeightening on Sep. 12-13. The rising part was detected on Sep. 12.

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[vsnet-campaign-dn 16502] Gaia DR3 6708677485442815744 = ASASSN-22ku: superhump period
by Taichi Kato 09 Sep '22

09 Sep '22

Gaia DR3 6708677485442815744 = ASASSN-22ku: superhump period Berto Monard and Josch Hambsch reported observations. The period of stage B superhumps (since Sep. 5) is 0.07412(3) d. The period given in vsnet-alert 26925 was not correct.

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[vsnet-campaign-dn 16501] Gaia DR3 6708677485442815744 = ASASSN-22ku: new SU UMa-type dwarf nova
by Taichi Kato 07 Sep '22

07 Sep '22

Gaia DR3 6708677485442815744 = ASASSN-22ku: new SU UMa-type dwarf nova Berto Monard and Josch Hambsch reported observations. The object started to show superhumps on Sep. 3. The current period (likely stage A or A/B mixed, amplitude already 0.12 mag) is 0.07042(5) d. Superhumps were not evident on Sep. 2.

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